If you're in NSW, you may have seen those "check speed" signs with flashing lights mounted near the large "school zone" signs which mark the areas around schools where children will be present before and
after school. They're the result of a lot of political pressure - and
heartache - by Peter Olsen over the past six years. Of particular
interest to SILICON CHIP, they're powered by PICAXE microcontrollers.

Many homes have had solar panels installed over the last few years, usually ranging from about 1.5kW up to 4kW. But how safe are they, especially if they have been installed in a rush to meet subsidy deadlines?

Most readers will have heard of the Square Kilometre Array (SKA) radio telescope project which SILICON CHIP reported on in the December 2011 issue. It was supposed to be a bidding contest between Australia and South Africa. In simple terms, South Africa won and we lost. But that's not the end of the story.

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Most DCC base stations have puny current capabilities which are exposed if you want to run more than a few locos and peripherals on your model railway layout. Problem is, DCC boosters are expensive, with a well-known 5A booster costing over $200. Problem no longer; build this 10A beauty at a fraction of the cost.

Did you know that you can convert the flea-power motors from old CD or DVD-ROM drives to high-power operation - eg, for model aircraft or other demanding uses? While it may seem improbable it is relatively easy to do, the main change being to fit Neodymium 'Rare Earth' magnets. Oh, you also need to find some suitable motors.

Built in Australia more than 50 years ago, this AWA 157P 7-transistor radio is still in good condition and required only a few minor repairs to restore it to working order. It's built like a valve receiver, with point-to-point wiring and no printed circuit board.

When breadboarding or prototyping, sometimes you need to experiment with a capacitor value. Substituting a range of different capacitors can be a bit tedious. What you need is a capacitance decade box, which makes it easy to find the right value for your circuit.